DirectionOpt sets the layout direction for the group's items.

func DirectionOpt(d Direction) GroupOption {
	return func(c *groupConfig) {
		c.direction = d
	}
}

GroupA11yLabel sets the accessibility label for the radio group.

func GroupA11yLabel(s string) GroupOption {
	return func(c *groupConfig) {
		c.a11yLabel = s
	}
}

GroupDisabled sets the group's disabled state. A disabled group does not

respond to user input and all items are drawn with a dimmed appearance.

func GroupDisabled(d bool) GroupOption {
	return func(c *groupConfig) {
		c.disabled = d
	}
}

GroupDisabledFn sets a dynamic function that is evaluated to determine

whether the group is disabled. When set, this takes precedence over the

static value but not over a signal set via [GroupDisabledSignal].

func GroupDisabledFn(fn func() bool) GroupOption {
	return func(c *groupConfig) {
		c.disabledFn = fn
	}
}

GroupDisabledReadonlySignal binds the group's disabled state to a read-only signal.

This is useful for computed signals created via [state.NewComputed].

When set, this takes highest precedence over all other disabled sources.

func GroupDisabledReadonlySignal(sig state.ReadonlySignal[bool]) GroupOption {
	return func(c *groupConfig) {
		c.readonlyDisabledSig = sig
	}
}

GroupDisabledSignal binds the group's disabled state to a reactive signal.

When set, the signal value takes precedence over both [GroupDisabledFn] and [GroupDisabled]

but not over [GroupDisabledReadonlySignal].

func GroupDisabledSignal(sig state.Signal[bool]) GroupOption {
	return func(c *groupConfig) {
		c.disabledSignal = sig
	}
}

GroupPainter sets the painter used to render each radio item.

Each design system provides its own painter. If not set,

[DefaultPainter] is used.

func GroupPainter(p Painter) GroupOption {
	return func(c *groupConfig) {
		c.painter = p
	}
}

Items sets the item definitions for the group.

Each ItemDef describes a single radio item's value and label.

func Items(defs ...ItemDef) GroupOption {
	return func(c *groupConfig) {
		c.items = defs
	}
}

OnChange sets the callback invoked when the selected item changes.

The callback receives the value of the newly selected item.

func OnChange(fn func(value string)) GroupOption {
	return func(c *groupConfig) {
		c.onChange = fn
	}
}

Selected sets the initially selected item by value.

If no item matches the value, no item is selected.

func Selected(value string) GroupOption {
	return func(c *groupConfig) {
		c.selected = value
	}
}

SelectedSignal binds the group's selected value to a reactive signal.

This is a TWO-WAY binding: the widget reads the selected value from the signal,

and when the user selects an item, the new value is written back to the signal.

When set, the signal value takes precedence over [Selected].

func SelectedSignal(sig state.Signal[string]) GroupOption {
	return func(c *groupConfig) {
		c.selectedSignal = sig
	}
}

ItemDef describes a radio item's value and display label.

type ItemDef struct {
	// Value is the programmatic identifier returned by [Group.Selected].
	Value	string

	// Label is the human-readable text displayed next to the radio circle.
	Label	string
}